Sitting in a Washington coffee shop in between meetings with senators, Laurie David considers the difference between once finding fresh comedians for David Letterman's Late Show and now finding fresh ways to enlist people in the fight against global warming.

"Dealing with politicians, that's a little different. But government doesn't change until people demand it," says David, 47, a producer of former Vice President Al Gore's documentary An Inconvenient Truth and April's HBO climate special, Too Hot Not to Handle. Elle magazine, which she co-edited in May, calls David, wife of Curb Your Enthusiasm's Larry David, "one of the most powerful environmentalists in America."

The critical acclaim for Gore's big-screen warning about the dangers of warming seems likely to only increase Laurie David's influence and that of other celebrities getting the word out.

"We're talking about the climate of the planet," David says. "This is about as urgent an issue as there is."

Gore's movie has turned the spotlight on climate change, but scientists have long been concerned about rising temperatures fueled by increased concentrations of greenhouse gases in the atmosphere. Feared effects include rising seas, extreme weather and drought. Activists often focus on the need to cut emissions of carbon dioxide, one of the greenhouse gases, by burning less fossil fuel.

Celebrities often get knocked for speaking out, says David, who worked as a talent manager and comedy-special producer before turning to global warming full time a decade ago.

"Everyone has a right to speak out," she says. "I couldn't live with myself, with the opportunity I have, if I didn't try to do everything I could."

Other celebrities are talking about global warming:

• Brad Pitt will narrate Design: e2, a series about environmentally friendly architecture. The series is scheduled to air in June on PBS.

• Keanu Reeves and singer Alanis Morissette narrate The Great Warming, a climate documentary that had its U.S. premiere in April.

• On Leonardo DiCaprio's Web site, the actor narrates a short global-warming primer. He's also working on an environmental documentary, called 11th Hour, according to the site.

• Oscar winner Joanne Woodward, a longtime supporter of the Nature Conservancy, spoke out on Earth Day, calling for action.

And Gore has blended Hollywood with Washington in a high-profile way that has some pundits saying the effort could pave the way for a second Gore campaign for the White House.

David's most ambitious effort may be the Stop Global Warming Virtual March, an effort to build an Internet coalition. She says more than 360,000 people have joined.

umm....i don't know.....when movie stars get on an issue, it becomes more of a fad than a cause and it always loses steam after a brief period.

personally, i wish they'd (the stars) would just stick to acting and leave the "causes" to people who really care. somehow, people driven around in chauffeured hummers of limosines, don't strike me as people i might want on my side to fight against global warming....

well, i was across the street in the woods one day and i found some growing wild. at least i thought they were mint plants. they looked like mint leaves and smelled like mint....very much. so, i picked a bunch and brought them home.

i planted some near a drainage ditch...don't ask me why...i just did....and this year they were over grown so much they blocked the water from draining...argh!! so, i had to rake them all out....so many that they filled my garden trailer....lol dumped them back across the street.

some others i planted near the garage. now those also are spreading like weeds. what were they supposed to keep away again? was it ants? well, i still see ants in the driveway, but i'm not sure i want those damn mint plants around the house. they spread like wild fire.

My mint plants have never taken over any area, but growing conditions are different. My neighbor has a whole patch of lily of the valley--I can't grow one plant. I have great honeysuckle bushes, she can't get any to grow. Nature is strange.

Yes, it is ants the mint is supposed to keep away. Maybe you should just pick some of the leaves from the wild plants and dry them, put them around here and there to keep ants away.

Actually, the best pest control is tobacco. My mother used to buy a pack of cigarettes and put them singly around here and there. Out of the reach of children and animals of course. But then cigarettes were about 25 cents a pack back then too.